Surat Al-Ĥujurāt - سورة الحجرات

إِنَّ الَّذِينَ يَغُضُّونَ أَصْوَاتَهُمْ عِندَ رَسُولِ اللَّهِ أُولَٰئِكَ الَّذِينَ امْتَحَنَ اللَّهُ قُلُوبَهُمْ لِلتَّقْوَىٰ ۚ لَهُم مَّغْفِرَةٌ وَأَجْرٌ عَظِيمٌ

Muhsin Khan: Verily! Those who lower their voices in the presence of Allah's Messenger (SAW), they are the ones whose hearts Allah has tested for piety. For them is forgiveness and a great reward.